A byte mask is a collection of bits that indicates to memory systems which bytes of data are updated and which bytes are ignored. The byte mask typically contains one bit for each byte of data. Accordingly, a memory system analyzes each bit of the byte mask to determine whether a corresponding byte of data is updated or ignored.
Typically, memory buses in memory systems use byte mask lanes or pins to communicate byte mask information. These pins are dedicated to transmitting byte mask data. In other words, the byte mask lanes or pins and are not utilized when byte mask information is not required for a particular write operation. As one pin sends one bit of data, the number of byte mask pins required in a memory device is equal to the number of bytes typically sent during a write operation.
However, byte mask data is rarely required for write operations. Byte masks are necessary when individual bytes of write data are to be written and not the entirety of the write data. Accordingly, in the majority of memory write operations, the byte mask pins are idle. Thus, a portion of the external bus and pins are not heavily utilized and occupy valuable space in the memory device.